Climate dynamics and change in the equatorial Pacific: Implications for marine ecosystems

Upwelling across the Pacific Ocean is projected to weaken in accordance with a reduction of the atmospheric overturning circulation, posing a major threat to marine ecosystems. Of critical concern is that MPAs cannot provide refuge from the anticipated rate of large-scale warming of the tropical oceans, which likely exceeds the evolutionary capacity of coral and their symbionts to adapt. Here we show, using high-resolution satellite measurements together with global climate models, that warming and productivity decline around a select group of Pacific islands will likely be mitigated by enhanced upwelling associated with a strengthening of the equatorial undercurrent. Since the undercurrent is dynamically constrained to the equator, few ecosystems stand to benefit from this equatorial island effect; those that do stand the best chance of surviving the anticipated climate changes of the 21st century, providing refuge for keystone species and larvae to reseed damaged and less resilient areas.

Last updated: January 19, 2012

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